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data race

Two accesses to the same data at once, at least one writing, with nothing coordinating them.

A data race is unsynchronized concurrent access to the same memory with at least one write; its behavior is undefined.

Examples

  • Inside std::thread::scope, spawning two threads that both run count += 1 is rejected with E0499, so the race never gets to run.

See also

mutable reference borrow checker undefined behavior
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